65 to 80 days Click to see full answer. Accordingly, how long does it take for eggplant to grow? 100 to 120 days Additionally, how many eggplants do you get per plant? Eggplant Yield Estimates Keep in mind that Italian oval eggplants produce about eight fruits per plant, while Asian eggplants yield from 10 to 15 of the elongated fruits. One may also ask, how do you know when to harvest eggplant? Skin should be glossy and thin. Eggplant harvest may begin when the fruits are developed and small, but growing fruits to full size before harvesting eggplants results in more fruit for usage. Harvesting eggplants should occur when the inner flesh is cream colored, fruits are firm and before seeds are visible.How often do eggplants need to be watered?Eggplants are best watered approximately 1 inch per week during the growing season. This amount may increase during times of hot, dry weather. Monitoring the soil with a moisture meter will help ensure that the soil does not become dry between waterings.